This Friday afternoon at approximately 2:26 Eastern time, an asteroid roughly half the size of a football field (147 feet) in diameter will pass extremely close to the Earth—just 17,200 miles from our planet’s surface. That said, there’s no need to worry, as NASA scientists confirmed with certainty nearly a year ago that the asteroid will not make an impact and poses absolutely no threat.Nevertheless, the proximity of the asteroid’s path is noteworthy: it will come within a distance 2 times the Earth’s diameter, passing us by even closer than some geosynchronous satellites that broadcast TV, weather and radio signals. As Phil Plait writes in his comprehensive post on the asteroid over at Slate, “This near miss of an asteroid is simply cool. It’s a big Universe out there, and the Earth is a teeny tiny target.”
The asteroid—likely made of rock and referred to as 2012 DA14 by scientists—was first spotted last February by astronomers at Spain’s Observatorio Astronómico de La Sagra. Asteroids, like planets, orbit the Sun, and this one passed us by on its last orbit as well, but at a much greater distance—it came within roughly 1.6 million miles last February 16. After this year’s near miss, the rock’s orbit will be altered significantly by the influence of Earth’s gravity, and scientists calculate that it won’t come near us again until the year 2046 at the soonest.
On Friday, though, it will pass by Earth between 18:00 and 21:00 UTC (1-4 p.m. Eastern time, or 10 a.m.-1 p.m. Pacific) and come closest at roughly 19:26 UTC (2:26 p.m. Eastern, 11:26 a.m. Pacific). That means that observers in Eastern Europe, Asia and Australia get to see its closest pass at nighttime, whereas those in North America, Western Europe and Africa will have to wait until after sunset, when the asteroid has already begun to move away.
Written By: Joseph Strombergcontinue to source article at blogs.smithsonianmag.com